Determine the mass of a boy who can stand on ice withstanding a pressure of 2500 Pa if the area of the soles of his boots is 0.02 m2.

P = 2500 Pa.

g = 9.8 m / s2.

S = 0.02 m2.

m -?

We express the boy’s pressure not ice P by the formula: P = F / S, where F is the force with which he presses on the ice surface, S is the area over which this force is distributed, that is, the area of his soles.

The boy presses on the ice by the force of his weight F, the value of which is expressed by the formula: F = m * g, where m is the boy’s mass, g is the acceleration of gravity.

The formula for determining the pressure of the boy P will take the form: P = m * g / S.

m = P * S / g.

m = 2500 Pa * 0.02 m2 / 9.8 m / s2 = 5.1 kg.

Answer: ice can support a boy weighing no more than m = 5.1 kg.